docs: def cdn_for(endpoint, **kwargs):
      '''
      Get a CDN URL for a static assets.
  
      Do not use a replacement for all flask.url_for calls
      as it is only meant for CDN assets URLS.
      (There is some extra round trip which cost is justified
      by the CDN assets prformance improvements)
      '''
      if current_app.config['CDN_DOMAIN']:
          if not current_app.config.get('CDN_DEBUG'):
              kwargs.pop('_external', None)  # Avoid the _external parameter in URL
          return cdn_url_for(endpoint, **kwargs)
      return url_for(endpoint, **kwargs)